The present invention relates generally to improvements in electronic shelf label (ESL) systems used in transaction establishments. More specifically, the present invention relates to improvements in ESL systems including systems and methods for reducing ESL power consumption and extending ESL battery life.
ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of ESLs to display the prices of the merchandise items. The ESLs are coupled to a central server where information about the ESLs is typically maintained in an ESL data file which contains ESL identification information and ESL merchandise item information. The central server sends messages, including price change messages, to the ESLs.
An ESL includes a variety of components, such as, for example, a liquid crystal display (LCD), a transmitter, a receiver, ESL circuitry and memory, all of which may be powered by a battery. Replacing the battery in an ESL is a manual process which may involve a store employee going to the location of the ESL, removing the discharged battery and inserting a new battery into the ESL. Increasing the time between battery replacements would result in a lower cost of ownership for the ESL system owner by reducing both the number of replacement batteries which must be purchased and the amount of time store employees spend replacing the batteries. As ESLs are found in increasing numbers at retail establishments, the cost savings from the reduction of battery replacements can be significant.
Battery consumption by the display portion of the ESL is proportional to the number of display segments turned on. Thus, an ESL with segments turned on consumes more power than an ESL with no segments turned on. For example, the amount of power needed to operate a typical LCD with 50% of the segments turned on may be approximately one-third of the total power consumption of the ESL.
Therefore, it would be desirable to provide an ESL system and method that conserves battery power by removing power from at least a portion of the display when the ESLs are not being viewed or utilized.
The present invention advantageously provides methods and apparatus for an improved electronic shelf label (ESL) system. An ESL system in accordance with the present invention extends battery life and increases the time between battery replacements by turning off the display segments of an ESL""s display at predetermined times, such as, for example, when the store is not open or when the tags are not being viewed by customers. The extension of battery life results in a lower cost of ownership for the ESL system owner by reducing both the number of replacement batteries which must be purchased and the amount of time store employees spend replacing the batteries. If a blank display is undesirable, due to possible confusion with a malfunctioning ESL or battery outage, then a single segment or a limited number of segments may be turned on. In one aspect, one of an ESL""s registers which contains the display contents may be loaded with a xe2x80x9cblankxe2x80x9d indication, or spaces (the lack of visible characters), which results in the ESL not displaying any text and all of the display segments being turned off.
In a preferred embodiment, the register containing the xe2x80x9cblankxe2x80x9d indication is a reserved register and is located at the same register address for all ESLs in a retail establishment, allowing a single broadcast message to be transmitted to all ESLs to turn the displays off. By using such a broadcast message, an entire retail establishment may have its ESLs turned off quickly, rather than having to address each of the ESLs individually. Prior to the store reopening, a second broadcast message may be transmitted to cause the ESLs to resume normal displays.
A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following detailed description and the accompanying drawings.